US3002757A

US3002757A - Golf club head

Info

Publication number: US3002757A
Application number: US769331A
Authority: US
Inventors: Emil J Marciniak
Original assignee: AG Spalding and Bros Inc
Current assignee: 1801 SPIELBUSCH AVENUE Inc A DE CORP; AG Spalding and Bros Inc
Priority date: 1957-12-17
Filing date: 1958-10-24
Publication date: 1961-10-03
Anticipated expiration: 1978-10-03

Description

4 Claims. (Cl. 2734-174) 'This invention relates to golf club heads rand more particularly to wooden golf heads impregnated with Vinyl resins for rendering the headjresistant orn immune to the efects of moisture suchl as swelling, deformation, and eventual deterioration, otherwise to improve its physical character, to change its physical properties, to toughen it, and generally giving itthose characteristics which it is desired tohave imparted thereto.

This `application isl a ldivision of, my copending appli- `cation Serial No. 703,343, tiled December 17, l1957 and since matured into Patent No:2,936,248.

Heretofore heads have been impregnated with matelrials but they did not havefa low' moisture transmission and did not prevent swelling. lAlso a method has been employed in which a `iluid .pelymerizable lnon-stabilizfed resin or monomer is 'fused in sucha'manner as to allow the monomer to polymerize after it has, penetrated into the wood, with the attendant diiiiculty of controlling'polymerization. f' e A This method has resulted `in a majrdrawback, namely resin exudation, 4which may occur subsequent` to penetration and after the heads have been removed from the impregnating bath to be) dried, with undesirable surface tackiness accompanying` suchuexudation. This has been a problem of longstanding which heretofore required special and expensive finishing treatment steps.

It is among the objects of, this invention to provide an impregnated golf "head having improved properties and characteristics "involvingauniform deep penetration into the head as well as optimum and lasting moisture-resistant resin impregnation of the article without the accompanying exdation and `surface tackiness heretoiore experienced.v p Y i This is accomplished byV employing `an impregnating resin in the form of `a `vinylpolymer-or copolymer thereof in Aa mixture of solvents of the class of ketones and of the class of aromatic hydrocarbons, preferably such solvents having differentV vapor pressures and different evaporation rates at room temperature so as to provide an impregnating solution of low viscosity and high penetrating power and by subsequently controlling the rate of evaporation of the solvents iiromthe club head in a manner to discourage and avoid resin exudation. W Y

According to one method employed for impregnating the heads of the present invention, the heads are immersed in a bath ofthe impregnatingsolution at atmosphericpressureior a-predetermined length of time sucient to permit the desired penetration, after which the. heads are removed and subjected Ato a partial drying at room temperature during which time the ketone solvent evaporates morefrapidly than the aromatic hydrocarbon solvent from the surface of the head and, in effec-t, builds up a resin barrier which prevents exudation of the resin t when the heads are thereafter subjected to a drying period at a high temperature-to complete the evaporation of the solvents therefrom. n A u K v Another method of forming the heads of the present invention is to subject 'the heads to vacuum until a,

Inited States Patent() 3,002,757 Patented Get. 3, 1961 stable condition is achieved and thereafter impregnating the head at high pressure with the impregnating solution. This procedure greatly shortens the time for treating the head and'permits a higher solid content of the solution to be used and still `achieve the desired penetration. Thereafter the head is removed and partially dried at room temperature land then completely dried at an elevated tempera-ture as before.

By so impregnating the head I am able to control the weight of the head so as to eliminate unneocessary coring in order to insert weights as has been the prior practice; I iam able to produce amore stable head in that the iibers in the head are adequately coated with the resin; an improved toughness of the material of the head `is achieved, all with the added result that the head has a low moisture transmission and is more resistant to taking on moisture and swelling in use.

Other features and advantages will be apparent from the specification and claims when considered in connection with the dravlngs in which:

FIGURE lis a side View, partly in section, of a wooden golf club head.

FIG. 2 isa view,'partly in elevation, taken on line 2-2 of FIG. 4l.

FIG. 3 is a sectional view taken on line '3-3 of FIG. l. A

The golf club4 head 10 is made of wood, preferably persimmon, and is shaped to the required shape. It is then impregnated with an impregnating solution comprising a polymerized resin and a mixture of solvents of the class of ketones and ofthe class of aromatic hydrocarbons, which solution has a low viscosity and high penetrating power so that the impregnation will extend into the head a substantial distance from all faces thereof as indicated by heavy shading in the sectional views or the drawings. lAfter the solvents have been removed, there will be incorporated in the head the polymerized resin so that the head has a low moisture transmission copolymers thereof such `as polyvinyl chloride and 'copoly- Amers ythereof'may be used. These resins are such that when impregnated into the body of the head they tend to coat the wood fibers and to toughen the head. Also,

heads impregnated with polyvinylidene chloride particularly have a low moisture transmission and substantially resist the passage of moisture into the head and the wood fibers thereof` so as to prevent undesirable swelling of the head. The resin soincorporated in the head tends also to add weight to the head in desired amounts to control the weight of the head as required. With the heads of the present invention coring thereof, as now employed for the insertion of the usual weights in the head, is eliminated or greatly reduced.

TheV ketones `usedin the solution are those whichfdissolve the resin, reduce the viscosity of the solutiomsw'ell the wood to permit better penetration of the solution and have .a high evaporation rate. While diethyl ketone, methyl ethyl ketone, methyl isobutyl ketone and the like may be used, it is at present preferred to use acetone.

'The aromatichydrocarbons used in the solution are those whichhave some solvent effect on the resin, cause the" solution to have a greater penetration into the wood and act to stabilize the solution. Also they are the "ones whichcanbe readily evaporated fromn the head, although encarar they have a lower evaporation rate than the ketonesl pressure, a 12% solution has been found to be highly satisfactory. This, of course, can vary slightly in either direction depending upon the density and nature of the wood of the head. When pressure impregnation is employed wherein the solution is forced into the pores of the head under substantial pressure, solutions of between 24 to 27% have been found most satisfactory. However, here again this percentage may vary slightly above and below these Values depending upon the nature of the head,`

i.e., the density of the wood and other characteristics affecting the penetration of the resin.

l It will be noted from the shading in the drawings that the impregnating resins extend a substantial distance in from each surface of the head. With this depth of penetration, the

grooves

11, 12 for the usual face plate 13 and sole plate 14 in the face 15 and bottom surface 1.6 can be safely cut since there is substantial resin content inwardly of these cuts so that passage of moisture into the head through the cuts is effectively prevented. Further the face plate can be cemented in position by means of an epoxy resin which not only adheres the face plate, which may be of plastic, fiber or the like material, to the head but also aids in sealing the cut and preventing moisture from passing into the head. Similarly, the sole plates can and 2 so that the passage of moisture along the screws r Y and into the head is substantially eliminated.

It will be seen, therefore, that I have provided a novel golf head of the wood type which is impregnated with a polymerized resin, preferably polyvinylidene chloride, to

evaporated slowly from the surface of the heads and the resin therein will set up a barrier to the exudation of the resin from the head as the remainder of the solvent is driven off from the head. Higher temperatures at this time would build up vapor pressures in the head and drive out the resin. The heads are thereafter finish-dried in a heating chamber or hot room having a good circulation of air therein and being at a temperature of approximately 150 F. for 24 hours or 125 F: for 40 hours, after which the heads are removed and processed into golf clubs.V

' If the heads are to be pressure impregnated they are inserted in a vessel and vacuum of up to 25 inches of mercury applied to the vessel and the vacuum is maintained on the vessel fora period of 10-30 minutes or until the reading becomes stable indicating a complete evacuation of the heads. The vacuum-is shutolf and the impregnating solution is placed in the vessel under a minimum of 90 pounds p.s.i. pressure. Since the impregnating material is ,being forced into the heads under pressure, it can have a higher solid content. `At present, it is preferred to have a solid content of 24%. The heads are left under pressure for 24 hours and are then removed and air dried at room temperature for from 4-12 hours. Thereafter they are dried in the hot room at a temperature of 150 F. for 24 hours. f

The feature of applicants novel methods-resides in the fact that a deep penetration is obtained and that the heads are partially dried at roomv temperature after they are taken from the solution which sets up a barrier in the surface of the heads which prevents exudation of the resin while permitting the solvents to be removed at the high temperature, thus producing an improved head.

Variations and modifications may be made within the scopel of the claims and portions of the improvements may be used without others. Y

I claim:

1. AV golf club head comprising a wooden head im pregnated with a self-sealing residue, after evaporation,

an extent which effectively prevents the swelling of the head and which resin coats the fibers of the head to, in effect, seal them from moisture, and which is provided with a smooth outer surface since the impregnation of the head by my novel method prevents exudation of the resin from the head during drying thereof.

The head of the present invention can be produced by impregnation at atmospheric pressure or by a pressure impregnation process. Each of these processes will be described and in order to clearly understand the processes specitic values utilized in each are being given by way of example.

In the process wherein the heads are impregnated at atmospheric pressure, the heads are permitted to stand and are air dried for a period of at least a week. They are then immer ed in a tank of impregnating solution for a period of approximately 66 hours. The solution comprises a resin, preferably a polyvinylidene resin (Geon 222) dissolved in a solvent comprising half acetone and half toluene. The solution has a 12% solid content. Such a solution can be produced from 5 gallons acetone, 5 gallons toluene and 9.45 pounds of resin, which solution is vigorously agitated during the mixing thereof. The viscosity of the solution at 75 F. or room temperature is 19-20 seconds as determined by a Zahn No. 2 cup and the specific gravity is .881.

After the heads have been immersed for 66 hours they vare removed from the solution and are partially dried at room temperature of between 60 100 F. for from 4 to l2 hours aud preferably for 12 hours at 75 F. I have found that this is an important step in preventing exudation from the heads. A possible explanation of this discovery is that acetone which has a relatively high evaporation rate, it being about 5-1 with respect to toluene, is

of a deep penetrating solution comprising a vinyl resin, a solvent having a low evaporation rate and a solvent having a higher evaporation rate, said head being tough, having a high resistance to moisture transmission whereby swelling of the head therebyis resisted and being free of tackiness caused by resin exudation therefrom.

2. A golf club head comprising a wooden head impregnated with a self-sealing residue, after evaporation,

of a deep penetrating solution comprising polyvinylidene chloride, a ketone having a low evaporation rate and an aromatic hydrocarbon having a higher evaporation rate than the ketone, said head being tough, having a high resistance to moisture transmission whereby swelling of the head thereby is resisted and being free of tackiness head being tough, having a high resistance to moisture transmission whereby swelling of the head thereby is resisted and being free of tackiness caused by resin exudation therefrom.

4. A golf club head comprising a Wooden head impregnated with a self-sealing residue, after evaporation, of a deep penetrating solution comprising polyvinylidene chloride, acetone having a low evaporation rate and toluene having a higher evaporation rate than the acetone, said head being tough, having a high resistance to moisture transmission whereby swelling of the head thereby is resisted and being free of tackiness caused by resin exudation therefrom, a sole plate for the head, and means for securing the sole plate to the head including screws coated with epoxy resin and extending into the head.

(References on following page) References Cited in the le of this patent UNITED STATES PATENTS Rose June 15, 1926 Booty et al Dec. 20, 1938 Arnold etal Nov. 16, 1943 Cheyney Jan. 15, 1946 Wiles Nov. 7, 1950 6 Aust-in Apr. 8, 1952 Greenlee Nov. 16, 1954 OTHER REFERENCES Industrial and Engineering Chemistry for March 1942, pages 327-332 cited.

Industrial and Engineering Chemistry for April 1943, pages 422428 cited.

Claims

1. A GOLF CLUB HEAD COMPRISING A WOODEN HEAD IMPREGNATED WITH A SELF-SEALING RESIDUE, AFTER EVAPORATION, OF A DEEP PENETRATING SOLUTION COMPRISING A VINYL RESIN, A SOLVENT HAVING A LOW EVAPORATION RATE AND A SOLVENT HAVING A HIGHER EVAPORATION RATE, SAID HEAD BEING TOUGH, HAVING A HIGH RESISTANCE TO MOISTURE TRANSMISSION WHEREBY SWELLING OF THE HEAD THEREBY IS RESISTED AND BEING FREE OF TACKINESS CAUSED BY RESIN EXUDATION THEREFROM.